Forming head and process for the production of a non-woven fabric

ABSTRACT

The invention concerns a forming head for an apparatus for the production of a non-woven fabric by depositing fibers on a conveyor belt, comprising a fiber feeder which opens into a fiber processing chamber and which has a lower deposit opening for the delivery of fibers, wherein arranged in the fiber processing chamber are interengaging needle rollers with longitudinal axes oriented in mutually parallel relationship, which can rotate about their respective longitudinal axis, and the interengaging needle rollers enclose an inner chamber and are arranged with respect to the fiber feeder and the deposit opening in such a way that fibers fed to the forming head in operation enter the inner chamber by passing through between interengaging needle rollers and leave the inner chamber also by passing through between interengaging needle rollers.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is for entry into the U.S. national phase under §371for International Application No. PCT/EP05/051971 having aninternational filing date of Apr. 29, 2005, and from which priority isclaimed under all applicable sections of Title 35 of the United StatesCode including, but not limited to, Sections 120, 363 and 365(c), andwhich in turn claims priority under 35 USC §119 to German PatentApplication No. DE 10 2004 021 453.0-26 filed on Apr. 29, 2004.

BACKGROUND OF THE INVENTION

1. Technical Field

The invention concerns the production of fabric, and more particularly,the production of non-woven fabric.

2. Discussion of Related Art

The invention concerns on the one hand a forming head for an apparatusfor the production of a non-woven fabric and on the other hand a processfor processing fibres for the production of a non-woven fabric. Theforming head has at least one fibre feed means which opens into a fibreprocessing chamber. The fibre processing chamber has a deposit openingfor the delivery of fibres for example on to a conventional,air-permeable conveyor belt, below which is arranged a so-called suctionbox. A plurality of needle rollers which engage into each other, withlongitudinal axes oriented in mutually parallel relationship, arearranged in the fibre processing chamber. The needle rollers arerotatable about their longitudinal axis.

Accordingly the process includes as process steps the feed of fibres toa forming head and the uniform distribution of the fibres on a conveyorbelt by means of the forming head.

Forming heads and processes of that kind are already known in variousdifferent forms, thus for example from WO 99/36623 or WO 03/016605.

The non-woven fabrics to be produced usually contain a mix of naturalfibres, for example cellulose fibres of cotton or loosened woodcellulose which has already been treated mechanically and/or chemically(fluff pulp), synthetic matrix fibres such as for example polyester,polypropylene or viscose as well as synthetic binding fibres such as forexample so-called bi-component fibres as well as for example asabsorption agents so-called super-absorbent polymers in particle form(SAP) or fibre form (SAF). Bi-component fibres usually have a coremelting at elevated temperatures (190-250° C.) of for examplepolypropylene (PP) or polyethyleneterephthalate (PET) which are enclosedby a sheath which melts at lower temperatures (140° C.) and whichcomprises for example polyethylene (PE), or are connected in anotherform (side-by-side, fibril type).

Non-woven fabrics of that kind are used for example as asemimanufactured article for the production of diapers and sanitarytowels, absorbent inserts for the foodstuffs industry or for insulatingmaterial.

An important process step in the production of such a non-woven fabricis for the fibre mix to be deposited as uniformly as possible on anair-permeable transport or conveyor belt. That deposit operation iseffected by means of a forming head in which the fibres are mixed. Thedeposit operation is assisted by a suction device (suction box) beneaththe conveyor belt, with which the fibres are sucked through theair-permeable conveyor belt towards the conveyor belt. The fibre mixeswhich are deposited in an admittedly tangled but uniform form aretransported on the conveyor belt in the form of a fibre bed for furtherprocessing in subsequent process steps, for example the effect of heaton the fibre bed, so that the polyethylene sheaths of the bi-componentfibres fuse together and stick together. Treatment with latex can alsobe effected. In addition it is possible for a plurality of fibre bedlayers to be deposited one upon the other in order in that way forexample to produce a multi-layer non-woven fabric or also only a thickernon-woven fabric.

The range of variations in the products which can be produced withconventional apparatuses and processes is usually restricted by virtueof the fact that only given kinds of fibres or fibre lengths are to beprocessed therewith, so that the known processes and apparatuses cannotbe used to produced non-woven fabrics which contain both relativelyshort fibres and also relatively long fibres, in one forming step. Thestate of the art includes installations in which the deposit of theshort and long fibres takes place in succession (EP 1 299 588) or with acard (WO 03/086709). Disadvantages here are the increased level ofmachine complication and expenditure and the low weights in relation tosurface area which can be achieved, if the fibres are provided by way ofa carding process.

Therefore the object of the invention is to provide an apparatus and aprocess which have a greater range of variations in respect of thefibres to be processed and thus in respect of the products to bemanufactured.

DISCLOSURE OF INVENTION

According to the invention that object is attained by a forming head ofthe kind set forth in the opening part of this specification, in whichthe interengaging needle rollers enclose an inner chamber and arearranged with respect to the fibre feed means and the deposit opening insuch a way that fibres which are fed to the forming head in operationpass through between interengaging needle rollers into the inner chamberand also leave the inner chamber between interengaging needle rollers.The forming head is accordingly of such a configuration that the fibresto be processed have to pass through between interengaging needlerollers at least twice and preferably a plurality of times on the wayfrom the respective fibre feed means to the deposit opening. In thatsituation, the interengaging needle rollers contribute in duplicaterelationship to rendering the distribution of fibres uniform. On the onehand they simply cause fibres which have already been separated offindividually to be distributed uniformly. Added to that is the fact thatthe interengaging needle rollers break up fibre lumps comprising fibreswhich are hooked together, and in that way provide for further fibreseparation. The latter operation can also be referred to as fibreopening. In that sense the forming head according to the invention has agreater fibre opening capacity than known forming heads. A furtheradvantage is that both long natural fibres, for example cotton cellulosefibres, and also short natural fibres, for example wood cellulosefibres, or also synthetic fibres, can be processed with the forming headaccording to the invention equally and in one step, in particular fibresof lengths of between 2 and 60 mm. Fibre beds of between for example 50g/m² and 2500 g/m² can also be produced in one step with the forminghead according to the invention. Hitherto, different apparatuses andprocesses were required for processing fibres of such different lengths.Thus for example long-fibre fibre beds of 10 g/m² to 80 g/m² can beproduced in one step with conventional forming heads, while short-fibrebeds of 50 g/m² to 2000 g/m² can be produced with the conventional airplacement process.

In a preferred embodiment the longitudinal axes of the needle rollersare connected to the needle roller carrier which is driven in rotationand the axis of rotation of which extends parallel to the longitudinalaxes of the needle rollers. In that way it is possible for the needlerollers to be caused to perform not only a rotary movement but also atranslatory movement. In that case, the needle rollers are preferablyeach at the same spacing relative to the axis of rotation of the needleroller carrier and are thus arranged on a notional cylindrical wallbelonging to a cylinder, the centre line of which is the axis ofrotation of the needle roller carrier. The needle rollers are alsodistributed uniformly on that notional cylinder wall so that they areeach at the same spacing from each other. The fibres which pass into andout of the inner chamber thus pass through the needle rollers which arerotating and at the same time moving with a translatory movement.

In that respect the rotary movement of the needle rollers is preferablysuch that mutually adjacent needle rollers rotate in a mutually oppositedirection of rotation, just as that also applies for meshing gears of atransmission. However in a preferred embodiment the interengaging needlerollers are not coupled together rigidly, for example by way of gears,but each have their own respective separate drive and can therefore alsobe driven for example at different speeds of rotation. For that purposethe needles of adjacent needle rollers are displaced relative to eachother with respect to the direction of the longitudinal axis of theneedle rollers so that needles of adjacent needle rollers do notcollide, irrespective of the respective rotary speeds. The needles arepreferably arranged on the needle rollers in longitudinal rows, morespecifically particularly preferably alternately displaced a little inthe peripheral direction of the needle roller, thus affording in eachcase a row of needles in a zig-zag shape. In that arrangement, theneedles of the individual needle rollers each project from a cylindricalneedle roller body to which the individual needles are fixed.

In principle the number of the needle rollers enclosing a respectiveinner chamber is any number and is at least 4. An arrangement of 8 or 12needle rollers however has the advantage that the transport direction inthe intermediate space between the needle rollers, which ispredetermined by the rotary movement of adjacent needle rollers indifferent directions of rotation, is such that the transport directionin mutually opposite intermediate spaces is respectively opposite, thatis to say is directed either towards each other (into the inner chamber)or away from each other (out of the inner chamber). The needle rollercarrier normally has a central shaft which is oriented concentricallywith respect to the axis of rotation of the needle roller carrier andthus on the one hand at least partly fills a part of the inner chamber,and on the other hand also serves for the transmission of rotationalforces along the shaft.

The fibre processing chamber of the forming head preferably has in theregion of the needle rollers side and end walls which surround theneedle rollers enclosing the inner chamber, in such a way that fibresare very substantially prevented from flowing past the inner chamberoutside the needle rollers. In addition the side walls which extend inparallel relationship with the axis of rotation and the longitudinaldirection of the needle rollers, above the inner chamber, are preferablycurved towards each other in such a way that there is a fibre entryopening which is constricted in relation to the outer diameter of theassembly of the needle rollers enclosing the inner chamber. That fibreentry opening is preferably of such a dimension that it correspondsapproximately to 1.5 to 2.5 times the free space which is presentbetween rollers bodies of mutually adjacent needle rollers. A fibreentry opening of that kind contributes to making a stream of fibres andalso an air flow through the inner chamber more uniform. In that casethe fibre entry opening is preferably arranged centrally above the innerchamber so that the fibres are fed as centrally as possible to therotating needle rollers which mesh with each other and which are movedwith a translatory movement.

Preferably a sieve is arranged beneath the inner chamber and isassociated with the deposit opening. That sieve preferably extends alonga notional cylinder wall segment corresponding to a notional cylinderwhose centre line is the axis of rotation of the needle roller carrier.

When using longer fibres of a length of 10 to 60 mm, the sieve ispreferably formed by sieve bars which extend at least approximatelyparallel to each other and to the longitudinal axes of the needlerollers and which are preferably of a round cross-section. Thecross-section of the sieve bars is preferably so selected that, indiameter, it corresponds approximately to half the fibre length of thelongest fibres to be processed. The spacing of the sieve bars from eachother also preferably corresponds to half the fibre length of thelongest fibres to be processed. A sieve of that kind acts as a diffuserin the aerodynamic sense and thus contributes to making the air flowuniform within the inner chamber. Thus, for a fibre bed deposited on theconveyor belt, that affords a uniform air flow between the fibre feedmeans for the fibres to be processed, and the suction box beneath theconveyor belt.

When using shorter fibres of a length of up to 10 mm the sieve is formedby wire mesh grids or steel plates which have long been known, withregular repetitive geometrical openings. The opening shapes can beround, stadium-shaped (oval) or rectangular. Their number, size andarrangement is dependent on the desired degree of opening, being therelationship between the total surface area of the sieve and thethrough-passage surface area.

In accordance with the apparatuses described hitherto theabove-specified object is also attained by a process of theabove-indicated kind, in which not only distribution of the fibres whichhave already been separated but also opening of fibre lumps and thusindividual separation of fibres is effected in the forming head, morespecifically by means of rotating, interengaging needle rollers. In thatcase the fibres are guided through between rotating and interengagingneedle rollers into an inner chamber and then leave that inner chamberby passing through between rotating, interengaging needle rollers.

For that purpose the needle rollers are preferably moved transverselywith respect to the direction of rotation of the needle rollers duringthe feed of the fibres to the inner chamber. The movement of the needlerollers (rotary movement and translatory movement) is preferably so setthat the fibres or at least a part of the fibres are fed to the innerchamber a plurality of times before the fibres leave a fibre processingchamber in which the inner chamber is disposed.

In addition, for carrying out the process, preferably an air flow isproduced, which passes from above downwardly through the inner chamber.That air flow is preferably rendered uniform by a sieve beneath theinner chamber. In addition the air flow is preferably passed above theinner chamber through a fibre entry opening which is constricted inrelation to the inner chamber. That also contributes to making the airflow uniform.

The invention will now be described in greater detail by means of anembodiment by way of example.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a part of an installation for the production of a non-wovenfabric with a forming head according to the invention, and

FIG. 2 shows a plan view of the forming head of FIG. 1.

DETAILED DESCRIPTION

The installation 10 shown in FIG. 1 for the production of a non-wovenfabric includes a forming head 12 arranged above a conveyor belt 14. Theconveyor belt 14 is air-permeable. The forming head 12 has a lowerdeposit opening 16 above the conveyor belt 14. A suction box 18 isarranged beneath the conveyor belt 14 and beneath the deposit opening16.

A directed air flow can be produced by means of the suction box 18through the forming head 12, out of the deposit opening 16, through theconveyor belt 14, and into the suction box 18.

Fibres which are deposited on the conveyor belt 14 by the forming head12 can be securely sucked on to the conveyor belt 14 by means of the airflow. Fibres deposited on the conveyor belt 14 by the forming head 12form a fibre bed (not shown) on the conveyor belt 14. By virtue of thefact that the conveyor belt 14 is continuously driven in circulation, acontinuous fibre bed can be produced on the conveyor belt 14 if fibresare at the same time continuously deposited on the conveyor belt 14 bythe forming head 12. That continuously produced fibre bed is fed tofurther processing stages (not further illustrated in FIG. 1), forexample stages in which the fibre bed is then pressed.

Further subsequent joining procedures can be envisaged; they depend onthe required properties of the product such as a small proportion ofadhesive or a high level of tearing strength, even in the moistcondition. Thus, besides water jet consolidation, application of highpressures at selected points and hydrogen bonding, mention may also bemade of ultrasound bonding, bonding by heating, for example with hotair, or by the use of latex dispersions.

The fibres forming a respective fibre bed are usually natural fibres,for example cellulose fibres, mixed with synthetic fibres, for exampleso-called bi-component fibres. The latter preferably have a core of PETor PP and are enclosed with a sheath of PPE. Upon being heated the PEsheath melts and causes a respective bi-component fibre to be joined toa natural or synthetic adjacent fibre or functional constituents. Suchfunctional constituents of the fibre bed, which are fed to the forminghead 12, can be for example super-absorbent polymers (SAP) which providethat liquids can be efficiently bound by means of a non-woven fabricproduced in that way. That property is particularly desirable when thenon-woven fabric is to be subjected to further processing to provideabsorbent articles such as diapers, sanitary towels or absorbentinserts.

The forming head 12 encloses a fibre processing chamber 20 into whichopen one or more fibre feed means 22—only one such fibre feed means 22is shown in FIG. 1. With a plurality of fibre feed means, fibres ofdifferent kinds, for example cellulose fibres or bi-component fibres aswell as further substances which are to be fed to the fibre bed such asSAP or odour-absorbent constituents can be fed independently of eachother. The fibre feed means 22 provides for a uniform feed of pre-openedfibres over the entire width of the fibre processing chamber 20, seeFIG. 2.

In a preferred variant, the fibre feed means provided is a volumetricmetering unit which is arranged centrally above the fibre processingchamber 20, that is to say not laterally, as shown in the Figures. Inthe preferred variant therefore the fibre feed is from above into thefibre processing chamber.

Arranged in the fibre processing chamber 20 is a needle roller carrier26 which is illustrated in FIG. 1 only by means of its central driveshaft 24 and which carries eight needle rollers 28 distributed uniformlyon a notional cylindrical peripheral surface. The cylindrical peripheralsurface of the needle roller carrier 26 is indicated by the dash-dottedline identified by reference 26. The needle roller carrier 26 can bebetter seen in FIG. 2.

Each of the needle rollers 28 has a needle roller body 30 with needles32 which are fixed thereto and which are arranged in rows in thelongitudinal direction of the needle roller body 30. The needles are ofa diameter of between 1 and 6 mm and preferably between 2 and 4 mm. Thespacing of the needles 32 from each other within a row is between 10 and20 mm and is typically of the order of magnitude of 15 mm.

As shown in FIG. 1 the needle rollers 28 engage into each other andsurround an inner chamber 34.

The needle roller carrier 26 is rotatable about its central shaft 24 insuch a way that all of the needle rollers 28 are to be moved in acircular motion on the path indicated by the dash-dotted line. For thatpurpose the needle roller carrier 26 has a central electric drive motor36.

Each needle roller 28 is driven by its own electric motor 38 so that theneedle rollers 28 can be rotated independently of each other. As can beseen from FIG. 2, for that purpose the needles 32 of mutually adjacentneedle rollers are arranged in mutually displaced relationship in thelongitudinal direction of the needle rollers so that the needles 32 ofadjacent needle rollers do not collide with each other when the needlerollers 28 rotate independently of each other.

Between the roller bodies 30 of adjacent needle rollers 28 there is arespective free space 40, into which the needles 32 of the adjacentneedle rollers 28 project. Fibres which are fed in the fibre processingchamber 20 by means of the feed means 22 above the needle rollers 28 andthus above the inner chamber 34 must enter the inner chamber by passingthrough the respective free space 40 and thus between meshing needlerollers 28. Equally, fibres must leave the inner chamber 34 again bypassing through one or more of the free spaces 40 between the adjacentneedle rollers 28.

Fibres which are fed to the fibre processing chamber 20 above the innerchamber 34 by means of the fibre feed means 22 therefore must pass atleast twice through the free spaces 40 between adjacent needle rollers28 before the fibres leave the fibre processing chamber 20 in the regionof the deposit opening 16. In doing that, the fibres pass through theinner chamber 34. In operation both the needle roller carrier 26 andalso the respective needle rollers 28 are driven in rotation so thateach needle roller 28 simultaneously performs a rotary movement and atranslatory movement along the dash-dotted line.

Respectively adjacent needle rollers 28 are driven in mutually oppositedirections of rotation so that, at the same rotary speed, they behavelike meshing gears. For a respective free space 40, the result of thisis that the needles 32 which project into the free space 40 predeterminea fibre transport direction which is either directed into the innerchamber 34 or out of same. In that way fibres can pass into the innerchamber 34 a plurality of times in the desired manner and can beconveyed out of same again before finally they leave the fibreprocessing chamber 20 through the deposit opening 16.

The number of 8 needle rollers, shown in FIG. 1, just like analternatively possible number of 12 or 16 needle rollers, affords theadvantage that the transport direction within diametrally opposite freespaces 40 is opposite, so that in the situation shown by way of examplein FIG. 1, fibres are not transported through the upper free space intothe inner chamber 34 and immediately leave the inner chamber 34 againthrough the lower free space.

To make the fibre bed which is to be produced by means of the forminghead 12 uniform, a sieve 42 which is curved in a cylinder-likeconfiguration is provided beneath the needle rollers 28. In theembodiment of the forming head which is preferred for processing longerfibres, that sieve is formed by a multiplicity of bars which extendparallel to the longitudinal axes of the needle rollers 28 and the axisof rotation of the needle roller carrier. Those bars are of a circularcross-section and are 2 cm in diameter. The spacing of the bars fromeach other is also 2 cm in each case. Such a sieve is suitable forfibres with a maximum fibre length (staple length) of about 40 mm. Thoseare fibre lengths as are usual in the case of cotton fibres and in thecase of viscose staple fibres.

As mentioned hereinbefore it is also possible, for other types offibres, to use sieves of conventional opening geometry, that is to saywith round or oval holes or longitudinal slots.

The spacing of the sieve 42 from the free ends of the needles 32 isbetween 1 and 30 mm and preferably between 1 and 10 mm.

For making the stream of fibres still more uniform, the side walls ofthe fibre processing chamber 20, in the region identified by reference46, are constricted inwardly so that this provides a constricted fibreentry opening above the needle rollers 28. The width thereof which canbe seen in FIG. 1 approximately corresponds to 1.5 to 2.5 times thewidth of a respective free space 40 between mutually adjacent needlerollers 28. Similarly to the situation in the region 46 above the needlerollers 28 constricted side wall regions 46 a can also be providedbeneath the needle rollers 28.

In addition the wedge-shaped configurations which remain between thepossibly constricted side walls of the fibre processing chamber 20 andthe needle rollers can be provided with fibre guide bodies 48 whichrestrict the free space between a respective side wall and the needlerollers. Those fibre guide bodies 48 are connected to the needle rollercarrier 26 and rotate therewith. Similar fibre guide bodies can also bearranged on the central shaft 24.

The drawing does not show freely rotating rollers which are arranged atthe underside of the side walls and which seal off the fibre processingchamber 20 beneath the sieve 42 with respect to the conveyor belt 14.

The following novel products can be manufactured with theabove-described apparatus and the mode of operation thereof:

A Non-woven Fabric for the Production of Tampons

Tampons are formed at the present time as non-woven fabrics withlong-fibre materials by means of a carding procedure, that is to say thefibres are deposited in the longitudinal direction with the forwardadvance direction of the endless deposited strips. In that situation,due to the directed form in which the fibres are deposited, an imbalanceis formed in terms of tearing strength between the forward advancedirection and transversely with respect thereto. The tearing strength isgreater in the longitudinal direction than in the transverse direction.

The long fibres of up to 60 mm which are deposited by the processesdescribed in this application provide for a different strength which isrendered uniform and which is improved for the area of use involved andwhich has positive effects on the tampon article.

For that purpose, the apparatus according to the invention uses theprocess according to the invention to produce a fibre bed of viscosefibres for tampons. Those fibres are either so-called trilobally shapedfibres or conventional round fibres or a mix of the two kinds of fibres.Typical fibre parameters are 1.7 to 6.7 dtex, of a length of between 20and 60 mm. A typical weight in relation to surface area for a non-wovenfabric for such a use is between 200 and 1000 g/m², depending on therespective type of tampon. Cotton fibres are sometimes used fornon-woven fabrics of that kind for tampons. Those fibres can also beprocessed with the described apparatus and the described process. Thedefinitive non-woven fabric can be composed of two or more layers. Eachof those layers can contain fibres of differing specification. After theoperation of forming the fibre bed, it is compacted with calenderrollers and delivered in the form of rolls or blocks as an intermediateproduct for the manufacture of finished tampons.

Non-woven Fabrics for the Automobile Industry

The apparatus described herein and the process also make it possible toprocess flax fibres or hemp fibres or similar natural fibres inthemselves or mixed with synthetic fibres. The fibre length of suchnatural fibres is typically 50 mm. As those fibres are a natural producthowever there are also those fibres which are shorter than 20 mm orlonger than 120 mm. The synthetic fibres can be either polypropylenefibres or polyester fibres, the dtex values of which are between 1.7 and20. The fibre length of the synthetic fibres is 12 to 38 mm for thisexample of product. The weight in relation to surface area of thecorresponding non-woven fabrics is typically between 1200 and 2500 g/m².

Carrier Non-Woven Fabrics as Supports for Further Layers to be Deposited

It is also possible to produce carrier non-woven fabrics involving aweight in relation to surface area of 40 to 100 g/m². Fibres used here,besides the above-mentioned fibres, are synthetic binding fibres, inparticular so-called bi-component fibres, whose dtex values are between1.7 and 20. The fibre length of the synthetic binding fibres is 3 to 36mm. The carrier non-woven fabrics can be the support for further layersto be deposited, with functional constituents, as they act as compactedcarrier non-woven fabrics for fibres and/or constituents such as catchfilters. For that purpose the carrier non-woven fabric is unwound on tothe conveyor belt 14 and the fibres and/or functional constituents aredeposited on the carrier non-woven fabric, instead of being deposited onto the conveyor belt.

Non-woven Fabrics for Hygiene Articles Such as Baby Diapers, SanitaryTowels, Incontinence Products and the Like

In the case of the above-indicated hygiene articles, there is a sidewhich faces towards the body. For that side use is made inter alia ofspecial non-woven fabrics which rapidly transport the liquid into thesubjacent absorbent core. A fibre bed which contains polyester fibres isproduced for the manufacture of such absorption non-woven fabrics(referred to as the acquisition or intake layer). Those polyester fibreshave dtex values of between 3.3 and 16.7 and are of a fibre length ofbetween 24 and 36 mm. After the operation of forming the fibre bed thefibres are bound with styrene butadiene rubber (SBR) or with anotherbinding agent such as EVA (ethylene vinyl acetate) or an acryl. Atypical weight in relation to surface area for non-woven fabrics of thatkind for hygiene articles is between 20 and 100 g/m².

Non-woven Fabrics for Use as Moist Cosmetic Skin Care Cloths

The described apparatus and the process can equally be used to produce anon-woven fabric which contains polypropylene fibres or polyester fibreswith dtex values of between 1.0 and 3.3 as well as fibre lengths ofbetween 24 and 38. For the purposes of liquid absorption, viscose fibresor fluffed-up wood cellulose pulp fibres (fluff pulp) can be mixed withthe polypropylene or polyester fibres, either in the form of a uniformmix or in layers. In subsequent processing steps the non-woven fabric iswater jet-consolidated or felted in some other fashion. In additionlatex can be applied to one or both surfaces of the non-woven fabric toprevent it from giving off fluff.

The four product variations last described show the great range ofvariations in the non-woven fabrics which can be produced by means ofthe described forming head. Products of that kind are not to be producedwith known air forming procedures and therefore themselves represent new(intermediate) products.

1. A forming head for an apparatus for the production of a non-wovenfabric by depositing fibres on a conveyor belt, comprising a fibre feedmeans which opens into a fibre processing chamber which has a lowerdeposit opening for the delivery of fibres, wherein arranged in thefibre processing chamber are interengaging needle rollers withlongitudinal axes oriented in mutually parallel relationship, which canrotate about their respective longitudinal axis, characterised in thatthe interengaging needle rollers (28) enclose an inner chamber (34),wherein the fibre feed means (22) is arranged outside the inner chamber(34) in such a way that fibres fed to the forming head (12) in operationmust pass through between the interengaging needle rollers (28) into theinner chamber in the direction extending transversely with respect tothe longitudinal axes of the needle rollers and must leave the innerchamber (34) also between the interengaging needle rollers (28) in adirection again extending transversely with respect to the longitudinalaxes of the needle rollers, and wherein the longitudinal axes of theneedle rollers are connected to a needle roller carrier which is drivenin rotation and the axis of rotation of which extends parallel to thelongitudinal axes of the needle rollers.
 2. A forming head according toclaim 1 characterised in that the longitudinal axes of the needlerollers are each at the same spacing relative to the axis of rotation ofthe needle roller carrier.
 3. A forming head according to claim 1characterised in that the longitudinal axes of the needle rollers areeach at the same spacing from each other.
 4. A forming head according toclaim 1 characterised in that a sieve is arranged beneath the needlerollers and associated with the deposit opening.
 5. A forming headaccording to claim 4 characterised in that the sieve is arranged in acylinder wall segment-like configuration beneath the inner chamber.
 6. Aforming head according to claim 4 characterised in that the sieve isshaped in the manner of a cylindrical wall segment of a cylinder, thecentre line of the cylinder at least approximately coinciding with theaxis of rotation of the needle roller carrier.
 7. A forming headaccording to claim 4 characterised in that the sieve is formed by sievebars extending at least approximately parallel to the longitudinal axesof the needle rollers.
 8. A forming head according to claim 7characterised in that the sieve bars are of a round cross-section.
 9. Aforming head according to claim 7 characterised in that the sieve barsare of a diameter which is matched to the length of the fibres to beprocessed, in such a way that the diameter approximately corresponds tohalf the length of the longest fibres to be processed.
 10. A forminghead according to claim 7 characterised in that the sieve bars are at aspacing from each other which is matched to the length of the fibres tobe processed, in such a way that the spacing of the sieve bars from eachother approximately corresponds to half the length of the longest fibresto be processed.
 11. A forming head according to claim 1 characterisedin that the fibre processing chamber is laterally closed in the regionof the needle rollers by side and end walls in such a way that the endwalls extend across the inner chamber transversely with respect to thelongitudinal direction of the needle rollers while the side walls extendparallel to the longitudinal axes of the needle rollers, wherein the endand side walls are so arranged with respect to the needle rollers thatfibres are very substantially prevented from flowing past the innerchamber enclosed by the needle rollers.
 12. A forming head according toclaim 11 characterised in that the side walls above the needle rollersare curved towards each other in such a way as to extend to close to theneedle rollers so that a fibre entry opening is provided above theneedle rollers.
 13. A forming head according to claim 12 characterisedin that the needle rollers have a closed roller body and needles whichproject therefrom so that a respective free space is provided betweenthe roller bodies of adjacent needle rollers, wherein the fibre entryopening is approximately 1.5 to 2.5 times as large as the free spacebetween the roller bodies of directly adjacent needle rollers.
 14. Aforming head according to claim 1 characterised in that, distributedover their respective periphery, the needle rollers have a plurality ofrows, extending along the longitudinal axis of the needle roller, ofradially projecting needles which, in the case of adjacent interengagingneedle rollers, are arranged displaced along the respective row in thelongitudinal direction with respect to the adjacent needle roller insuch a way that the interengaging needle rollers can rotateindependently of each other.
 15. A forming head according to claim 1characterised in that, distributed over their respective periphery, theneedle rollers have a plurality of rows, extending along thelongitudinal axis of the needle roller, of radially projecting needleswhich within a respective row are arranged displaced alternately in theperipheral direction of the needle roller, thereby affording arespective needle row of a zig-zag configuration.
 16. A forming headaccording to claim 1 characterised in that the inner chamber is enclosedby eight or twelve needle rollers.
 17. A forming head according to claim1 characterised in that each needle roller has its own drive motor,preferably a respective electric motor.
 18. A forming head according toclaim 1 characterised in that the needle roller carrier has a shaftextending centrally through the inner chamber.